The parents of a 2-year-old who fell into a wild African dogs exhibit have sued the Pittsburgh Zoo & PPG Aquarium, claiming there was ample warning that parents routinely lifted children onto a railing so the kids could see better.

Pallbearers carry a small casket into a Mt. Lebanon church, while hundreds of toy trucks continue piling up at the funeral home where Maddox Derkosh was mourned. "Trucks For Maddox" will help a kids' Christmas charity.

Six months ago, toy trucks filled a funeral home with donations coming from Pittsburgh to Hong Kong. Now, Jason and Liz Derkosh have launched the Trucks for Maddox charity in memory of their 2-year-old son.

The zoo has just given its formal response to the lawsuit filed in May by the family of 2-year-old Maddox Derkosh, who died when he fell into the African painted dog exhibit at the zoo.

Maddox's mother, Elizabeth, 34, of Whitehall, was holding the boy above a railing when the child fell into the exhibit and was fatally attacked by the wild dogs in November.

In their lawsuit, the Derkosh family said the zoo failed to provide adequate protection to the public and failed to heed warnings about the exhibit from its own staff.

But in its response, the zoo says in a court filing that Maddox's death was "caused solely by the carelessness, negligence and/or recklessness of Elizabeth Derkosh."

The zoo says she was at fault for placing Maddox on top of or over the railing; failing to hold onto him; and failing to assess the physical environment at the exhibit.

The zoo also says the railing at the exhibit was tilted 45 degrees toward visitors in order to prevent visitors -- including children -- from sitting or standing on it.

The zoo also said it is immune from liability in this case because the zoo property is owned by the city of Pittsburgh and the city actually built the African dogs exhibit.

"The motions filed by attorneys representing the Pittsburgh Zoo are the next steps in the legal process," the zoo said in an email Wednesday. "Our attorneys have supplied the court with written responses and our position to the claims filed. We are unable to comment further, pending litigation."

Attorney Robert Mongeluzzi sent this response by email: "Maddox Derkosh was fatally attacked and killed at the Pittsburgh Zoo. The Zoo, in its court filing, attacked Maddox's grieving mother although the Zoo had been warned by several of its own employees of the very tragedy that would take Maddox's life, ignored the warnings, and told at least one of those employees that 'this is not your concern, go back to work.' On behalf of the Derkosh family, we look forward to proving, in discovery and at trial, that the Zoo's position is dead wrong and shameful."

3 Amber Nicotra/Highland Park IT WAS A TRAGEDY THAT CAPTURED INTERNATIONAL ATTENTION. AND NOW, SEVERAL MONTHS LATER, THE PITTSBURGH ZOO AND THE LITTLE BOY'S FAMILY ARE IN A LEGAL BATTLE AS TO WHO IS AT FAULT.áávoáá IT WAS NEARLY A YEAR AGO, WHEN LITTLE MADDOX DERKOSH WAS KILLED. THE TWO YEAR OLD BOY FELL INTO THE AFRICAN PAINTED DOG EXHIBIT LAST NOVEMBER AND WAS MAULED TO DEATH BY THE WILD DOGS. IN MAY, THE BOY'S PARENTS FILED A LAWSUIT AGAINST THE ZOO, CLAIMING IT FAILED TO PROVIDE ADEQUATE WARNINGS FOR VISITORS AND IGNORED WARNINGS ABOUT THE EXHIBIT FROM ITS OWN STAFF. WE JUST LEARNED THE ZOO'S FORMAL RESPONSE. WHO CLAIMS MADDOX'S DEATH WAS QUOTE "CAUSED SOLELY BY THE CARELESSNESS, NEGLIGENCE AND/OR RECKLESSNESS OF ELIZABETH DERKOSH." WHO THEY SAY PLACED MADDOX ON "TOP OF" OR "OVER" THE RAILING. BUT THE FAMILY IS FIRING BACK. THEIR ATTORNEY SAYS THE ZOO HAD BEEN WARNED BY ITS OWN EMPLOYEES-- OF THE VERY TRAGEDY THAT WOULD TAKE MADDOX'S LIFE. ADDING.... "WE LOOK FORWARD TO PROVING, IN DISCOVERY AND AT TRIAL, THAT THE ZOO'S POSITION IS DEAD WRONG AND SHAMEFUL." Amber Nicotra/Highland Park THE FAMILY IS SEEKING UNSPECIFIED DAMAGES. 3 3 3

Hillary Clinton did not have a State Department email account while she served as America's top diplomat, a senior state department official said Monday, and instead used a personal email account during her four years on the job.